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Power Draw & UPS question
Posted: Thu Jul 11, 2013 9:03 am
by Capt Jack
So, after losing power 7 hours into a 15 hour print last night
, I was wondering if anyone has their printer on a UPS?
If so, what watt/voltage UPS are you using? I know that the power supply is 450w, but does anyone know what the ACTUAL draw is while printing with the bed on?
Mood: Irritated.
Re: Power Draw & UPS question
Posted: Thu Jul 11, 2013 9:21 am
by foshon
The issue with a UPS won't be whether or not it can power the printer, most are able to power a computer and it's monitor. The issue is the length of time it will keep it running. Most backups are set up for large output for a short period of time, not long enough to finish a print. You would also have to power the computer that is sending the g-code unless you run off a sd card. There may even be issues with the printer seeing a power flicker when the UPS switches from AC to battery; it's very fast but not instantaneous.
Re: Power Draw & UPS question
Posted: Thu Jul 11, 2013 9:50 am
by Capt Jack
foshon wrote:The issue with a UPS won't be whether or not it can power the printer, most are able to power a computer and it's monitor. The issue is the length of time it will keep it running. Most backups are set up for large output for a short period of time, not long enough to finish a print...
My intent isn't to keep the printer going for very long...just long enough for the power to come back on. Outages are not that uncommon by me, but they are very short. Usually less than a few seconds (more like trips/switchovers than true outages). We've lost a refridgerator and washingmachine due to these trips/surges/etc., so a good UPS with surge protection is what I was looking at. It would have saved my print last night.
Re: Power Draw & UPS question
Posted: Thu Jul 11, 2013 10:03 am
by foshon
Cool, just wanted to make sure you had realistic expectations.
Re: Power Draw & UPS question
Posted: Thu Jul 11, 2013 10:12 am
by Capt Jack
foshon wrote:Cool, just wanted to make sure you had realistic expectations.
Unlike my wife, whom I continue to disappoint.
Re: Power Draw & UPS question
Posted: Thu Jul 11, 2013 1:07 pm
by kbob
The bed is ~110W peak. The hot end is ~40W peak. The motors are maybe 50W (probably less). The electronics are negligible. So 200W is the total load. Power supply is 80% efficient (maybe), so it draws 250W. Oversize that by 50% and look for 375W, or 530 VA. (VA = watts * sqrt(2). sqrt(2) = 1.4.) Bigger is, in this case, better.
Re: Power Draw & UPS question
Posted: Thu Jul 11, 2013 1:13 pm
by Capt Jack
kbob wrote:The bed is ~110W peak. The hot end is ~40W peak. The motors are maybe 50W (probably less). The electronics are negligible. So 200W is the total load. Power supply is 80% efficient (maybe), so it draws 250W. Oversize that by 50% and look for 375W, or 530 VA. (VA = watts * sqrt(2). sqrt(2) = 1.4.) Bigger is, in this case, better.
This is exactly what I needed!
Thanks!!!